Keeping Dirt Where It Belongs

If you’ve been to one of California’s wine regions, chances are you’ve seen hillsides carpeted in wildflowers or even vines, but how about vineyards carpeted in, well, carpet?

“Wool carpet is great for keeping soil in place,” says Julie Nord, vineyard manager and co-owner of Nord Vineyards, which farms 900 acres of vineyards in Napa Valley in addition to making wines under the Nord Estate Wines label. “It’s one of the best erosion control tools we have, plus, it’s a great way to recycle carpet that would otherwise get thrown into a landfill.”

Nord came up with the idea when a friend who owned a carpet business complained about all the used carpet they needed to dispose of. With acres of vineyards on steep and terraced hillsides, where soil erosion can be particularly problematic, Nord was looking for new ways to prevent the soil runoff that can occur during heavy rain events. Wool carpet, which has a jute backing and degrades naturally, seemed to be a perfect solution.

“We cut the carpet up into 2- or 3-foot wide strips and lay it between the vines,” says Nord, who notes that the first carpet she laid in her vineyards four years ago is barely visible now due to degradation. “Not only does it help with erosion, it also prevents evaporation of precious water when we irrigate.”

Of course not every California wine grape grower has a friend in the carpet business, and there are numerous ways of tackling the problem of erosion – an issue which every farmer faces.

“Vineyards, orchards, hay fields – they’re all established in nutrient-rich areas deposited over millions of years.All require some degree of tilling of the soil to create space for the products we wish to grow.This tilling turns under the existing grasses, bushes, etc, and exposes the soil so it can be farmed,” says Bill Cooper, winemaker at family-owned Cooper-Garrod Estate Vineyards in the Santa Cruz Mountains. ”The problem comes when a heavy rain causes the exposed top soil to run off or if a dry summer wind blows the soil away: think the Dust Bowl of the 1930s.”

The erosion control strategies that Cooper uses in their hillside vineyards are two of the most widely practiced among California wine grape growers today: no till farming and cover crops.

“We leave grassy strips between the vines that catch water and runoff soil, keeping them from going further down the hill,” says Cooper of his 28-acres of vineyard. “Rather than tilling the soil we simply mow the grasses, which leaves the root structure – and therefore the soil – in place.”

And like many California growers Cooper plants cover crops – a mixture of different grasses and flowers -- between the vine rows. Not only do these crops reduce the amount of exposed soil in the vineyard, they also attract certain types of birds and insects that are beneficial to the vines.In addition, his vineyards are small, ranging from 2 to 7 acres, and surrounded by unfarmed, natural habitat.

Both Nord and Cooper note that there are other ways to tackle the problem of erosion, some seasonal and some that are more permanent in nature. In addition to carpet, Nord places straw wattles (long, snake-like mesh tubes filled with straw) and hay bales at strategic places in her vineyards during the rainy season to keep water in place. Longer-term solutions include building culverts or gravel bars that direct the flow of water where the grower wants it to go.

Every new vineyard that gets planted in California has to have an erosion control plan, and in terms of sustainable practices, it’s one of the highest on every grower’s list. After all, as Nord says, “If we don’t have dirt, we can’t farm.”